Why is there night and day on Earth

Our schedule is tremendously influenced by day and night, these two periods being the ones that decide when we sleep and when we work and study. Night and day are vital to our life and we could not understand our world without both. To understand why our day is divided into these two periods, today in this lesson from a TEACHER we are going to talk about why is there night and day on Earth.

Our planet, the Earth is one of the celestial bodies that make up the Solar system, a planetary system in which the planets revolve around a large star called the Sun. For all this, the Earth is illuminated by the Sun, the period in which we receive sunlight is what we call day, and the period in which the Sun stops illuminating us, which we call night. Whether the Sun illuminates us or not is due to a process called rotation.

Rotation is one of the movements that the Earth makes, being the one in which the planet rotates on its own axis. The movement is carried out from west to east, that is, if we take the north pole as a point of view, the Earth rotates from right to left, and it takes a little less than

24 hours.

During the rotation, half of the planet is illuminated by the Sun and the other half is not, so it is dark. When rotating on itself, the Earth shows one face to the Sun each time, which is why in one part of the world it is day and in the other it is night, and that is why it changes every few hours. Although not all over the world it is night or day, but there is also a twilight zone located between both parts, this area being what we know as sunrise and sunset.

The length of day and night on Earth

The question that remains when knowing this information is the duration of the day and night, since when it comes to the position of the Earth Regarding the Sun and the movement of the Earth on the star, the logical thing would be that the day will last 12 hours and the night 12 hours, but that does not always happens. The duration of the day and night depends on the season in which we find ourselves, the average duration being 12 hours.

On the other hand, at the equinoxes, the day lasts more than 12 hours in spring and summer, with the summer solstice being the moment when the day happens. longer and the night shorter, on the other hand in autumn and winter the days last less hours, being when the shortest day and the longest night of the year.

From all this we can conclude that the reason why night and day exist is for the different position that each half of our planet occupies with respect to the Sun, due to the rotation of the Earth.

To conclude this lesson on why there is night and day on Earth we must talk about the different natural phenomena that make the day or night last much longer than normal, and the reasons that cause this.

One of these phenomena is "midnight Sun", an event that happens north of the Arctic Circle and south of the Antarctic Circle. The midnight sun is based on you the Sun is visible for 24 hours around the summer solstice. Few people can enjoy this phenomenon, being possible only for small populations near the pole of the northern hemisphere.

The other extraordinary natural phenomenon that changes the logical cycles of day and night is the so-called "Polar night". This event is based on the fact that the night lasts for 24 hours, and it usually happens in polar circles. Unlike the midnight sun, the polar night can be of different kinds depending on the type of twilight. The different kinds of polar night are as follows:

• Civil polar night: It is the period during which civil twilight does not occur.
• Nautical polar night: It is the period during which the nautical twilight does not occur and in which a dim light can be seen.
• Astronomical polar night: It is the period during which the astronomical twilight does not occur and no type of light can be seen.